A model for the weakening effect of very thin hard coatings

Effects of elastic modulus mismatch between coating and substrate on the friction and wear properties of TiN and TiAlN coating systems

“…[12,13] were obtained. Recently, Goltsberg et al [16] and Goltsberg and Etsion [17] studied the plasticity onset in coated spheres loaded by rigid flat using FEM. The results showed that the elastic modulus mismatch between the coating and the substrate may introduce additional stresses in the coating system to initiate premature plastic yield.…”

A comparison of stick and slip contact conditions for a coated sphere compressed by a rigid flat

“…This weakening effect was extensively studied and characterized in Ref. [28]. Further studies by Goltsberg and Etsion [29,30] provided universal relations for various contact parameters in the elastic regime of a coated spherical contact.…”

Indentation pop-in as a potential characterization of weakening effect in coating/substrate systems

“…It was found that the critical load of plastic yielding inception of the coated system is smaller than that of the uncoated substrate, indicating that hard coating weakens the system by reducing its load carrying capacity. Recently, Goltsberget et al [6] and Goltsberg and Etsion [7] studied the plasticity onset in coated spheres loaded by a rigid flat using FEM. The results showed that the additional stress in the coated system, which causes the weakening effect, is closely related to elastic moduli mismatch between the coating and the substrate.…”

“…[6,7]. In very thin hard coating systems, the coating can hardly shield the substrate from applied loads due to the limited thickness.…”

“…The main goal of the present study is therefore to characterize experimentally the weakening effect in hard coating/silicon substrate system by investigating its correlation to the pop-in critical load and comparing the experimental results with the theoretical models in Refs. [6,7].…”